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US 11,766,179 B2Granted
Determining flow speed and/or oxygen saturation based on photoacoustic imaging and sensing
AssigneeCity University of Hong Kong
InventorsLidai Wang, Chao Liu
Life of this patent
Estimating the term…
Abstract
A method and a method for determining flow speed based on photoacoustic imaging or sensing. The method includes receiving multiple photoacoustic signals from a sample in response to transmission of multiple laser pulses of different wavelengths to the sample, and processing the photoacoustic signals based on a flow model that relates photoacoustic signals with flow speed to determine a flow speed of a liquid flow in the sample.
Claims46
A method for determining flow speed based on photoacoustic imaging or sensing, comprising:
- receiving a first photoacoustic signal and a second photoacoustic signal from a sample in response to transmission of a first laser pulse and a second laser pulse to the sample, the first laser pulse has a first wavelength and the second laser pulse has a second wavelength different from the first wavelength;
- and
- processing the first photoacoustic signal and the second photoacoustic signal based on a flow model that relates photoacoustic signals with flow speed to determine a flow speed of a liquid flow in the sample;
- wherein the processing includes:
- determining a first amplitude of the first photoacoustic signal and a second amplitude of the second photoacoustic signal, and
- applying the first and second amplitudes to the flow model;
- wherein the flow model is an exponential decay model and relates the first and second amplitudes with flow speed by:
- P
- 2
- =
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- P
- 1
- +
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- P
- 1
- 2
-
- A
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- δ
-
- t
- where P1 is the first amplitude, P2 is the second amplitude, F1 and F2 are optical fluences associated with the first and second laser pulses, μa1 and μa2 are optical absorption coefficients associated with the first and second laser pulses, A, τα, and b are coefficients independent of the flow, δt is a time delay between the first and second laser pulses, ν is the flow speed.
61 more elements
A system for determining flow speed based on photoacoustic imaging or sensing, comprising:
- one or more processors arranged to:
- receive a first photoacoustic signal and a second photoacoustic signal from a sample in response to transmission of a first laser pulse and a second laser pulse to the sample, the first laser pulse has a first wavelength and the second laser pulse has a second wavelength different from the first wavelength;
- and
- process the first photoacoustic signal and the second photoacoustic signal based on a flow model that relates photoacoustic signals with flow speed to determine a flow speed of a liquid flow in the sample;
- wherein the one or more processors are arranged to perform the processing by, at least:
- determining a first amplitude of the first photoacoustic signal and a second amplitude of the second photoacoustic signal, and
- applying the first and second amplitudes to the flow model;
- wherein the flow model is an exponential decay model and relates the first and second amplitudes with flow speed by:
- P
- 2
- =
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- P
- 1
- +
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- P
- 1
- 2
-
- A
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- δ
-
- t
- where P1 is the first amplitude, P2 is the second amplitude, F1 and F2 are optical fluences associated with the first and second laser pulses, μa1 and μa2 are optical absorption coefficients associated with the first and second laser pulses, A, τα, and b are coefficients independent of the flow, δt is a time delay between the first and second laser pulses, ν is the flow speed.
62 more elements
A method for determining oxygen saturation in blood of human or animal in vivo based on photoacoustic imaging or sensing, comprising:
- receiving a first photoacoustic signal, a second photoacoustic signal, and a third photoacoustic signal from a human or animal in response to transmission of a first laser pulse, a second laser pulse, and a third laser pulse to the human or animal, the first laser pulse has a first wavelength, the second laser pulse has a second wavelength different from the first wavelength, the third laser pulse has a third wavelength different from the first wavelength and the second wavelength;
- and
- processing at least the first photoacoustic signal and the third photoacoustic signal based on a linear spectral unmixing model to determine oxygen saturation in blood of the human or animal;
- wherein the processing includes:
- determining at least an amplitude of the first photoacoustic signal and an amplitude of the third photoacoustic signal, and
- applying at least the amplitude of the first photoacoustic signal and the amplitude of the third photoacoustic signal to the linear spectral unmixing model;
- wherein the linear spectral unmixing model is represented by:
- sO
- 2
- =
- ε
- λ
- 3
- de
- -
- r
-
- ε
- λ
- 1
- de
- (
- ε
- λ
- 3
- de
- -
- ε
- λ
- 3
- o
-
- x
-
- y
- )
- -
- r
-
- (
- ε
- λ
- 1
- de
- -
- ε
- λ
- 1
- o
-
- x
-
- y
- )
- where sO2 is the oxygen saturation in the blood,
- r
- =
- μ
- a
-
- 3
- μ
- a
-
- 1
- =
- P
- 3
-
- F
- 1
- P
- 1
-
- F
- 3
- ,
- P1 and P3 are the amplitude of the first photoacoustic signal and the amplitude of the third photoacoustic signal respectively, F1 and F3 are optical fluences associated with the first and third laser pulses, ελ1,3de and ελ1,3oxy are molar extinction coefficients of oxyhemoglobin and deoxyhemoglobin at the first and third wavelengths.
75 more elements
A method for determining oxygen saturation in blood of human or animal in vivo based on photoacoustic imaging or sensing, comprising:
- receiving a first photoacoustic signal, a second photoacoustic signal, and a third photoacoustic signal from a human or animal in response to transmission of a first laser pulse, a second laser pulse, and a third laser pulse to the human or animal, the first laser pulse has a first wavelength, the second laser pulse has a second wavelength different from the first wavelength, the third laser pulse has a third wavelength different from the first wavelength and the second wavelength;
- and
- processing the first photoacoustic signal, the second photoacoustic signal, and the third photoacoustic signal based on a linear spectral unmixing model to determine oxygen saturation in the blood of the human or animal;
- wherein the processing includes:
- determining at least a first amplitude of the first photoacoustic signal and a third amplitude of the third photoacoustic signal, and
- applying at least the first and third amplitudes to the linear spectral unmixing model;
- wherein the linear spectral unmixing model is represented by:
- sO
- 2
- =
- ε
- λ
- 3
- de
- -
- r
- ′
-
- ε
- λ
- 1
- de
- (
- ε
- λ
- 3
- de
- -
- ε
- λ
- 3
- o
-
- x
-
- y
- )
- -
- r
- ′
- (
- ε
- λ
- 1
- de
- -
- ε
- λ
- 1
- o
-
- x
-
- y
- )
- where sO2 is the oxygen saturation in the blood,
- r
- ′
- =
- P
- 3
-
- F
- 1
- P
- 1
-
- F
- 3
- .
- 1
- 1
- +
- A
-
- P
- 1
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- 2
-
- δ
-
- t
- +
- AP
- 1
-
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- δ
-
- t
- ,
- P1, P2 and P3 are the first, second, and third amplitudes, F1, F2, and F3 are optical fluences associated with the first, second, and third laser pulses, δt is a time delay between the first and second laser pulses, as well as a time delay between the second and third laser pulses, A, τα, and b are coefficients independent of flow of the blood, μa1 and μa2 are optical absorption coefficients associated with the first and second laser pulses, ελ1,3de and ελ1,3oxy are molar extinction coefficients of oxyhemoglobin and deoxyhemoglobin at the first and third wavelengths.
126 more elements
A system for determining oxygen saturation in blood of human or animal based on photoacoustic imaging or sensing, comprising:
- one or more processors arranged to:
- receive a first photoacoustic signal, a second photoacoustic signal, and a third photoacoustic signal from a human or animal in response to transmission of a first laser pulse, a second laser pulse, and a third laser pulse to the human or animal, the first laser pulse has a first wavelength, the second laser pulse has a second wavelength different from the first wavelength, the third laser pulse has a third wavelength different from the first wavelength and the second wavelength;
- and
- process at least one of the first photoacoustic signal and the second photoacoustic signal, and the third photoacoustic signal, based on a linear spectral unmixing model to determine oxygen saturation in the blood of the human or animal;
- wherein the one or more processors are arranged to perform the processing by, at least:
- determining at least an amplitude of the first photoacoustic signal and an amplitude of the third photoacoustic signal, and
- applying at least the amplitude of the first photoacoustic signal and the amplitude of the third photoacoustic signal to the linear spectral unmixing model;
- wherein the linear spectral unmixing model is represented by:
- sO
- 2
- =
- ε
- λ
- 3
- de
- -
- r
-
- ε
- λ
- 1
- de
- (
- ε
- λ
- 3
- de
- -
- ε
- λ
- 3
- o
-
- x
-
- y
- )
- -
- r
-
- (
- ε
- λ
- 1
- de
- -
- ε
- λ
- 1
- o
-
- x
-
- y
- )
- where sO2 is the oxygen saturation in the blood,
- r
- =
- μ
- a
-
- 3
- μ
- a
-
- 1
- =
- P
- 3
-
- F
- 1
- P
- 1
-
- F
- 3
- ,
- P1 and P3 are the amplitude of the first photoacoustic signal and the amplitude of the third photoacoustic signal respectively, F1 and F3 are optical fluences associated with the first and third laser pulses, ελ1,3de and ελ1,3oxy are molar extinction coefficients of oxyhemoglobin and deoxyhemoglobin at the first and third wavelengths.
76 more elements
A system for determining oxygen saturation in blood of human or animal based on photoacoustic imaging or sensing, comprising:
- one or more processors arranged to:
- receive a first photoacoustic signal, a second photoacoustic signal, and a third photoacoustic signal from a human or animal in response to transmission of a first laser pulse, a second laser pulse, and a third laser pulse to the human or animal, the first laser pulse has a first wavelength, the second laser pulse has a second wavelength different from the first wavelength, the third laser pulse has a third wavelength different from the first wavelength and the second wavelength;
- and
- process the first photoacoustic signal, the second photoacoustic signal, and the third photoacoustic signal based on a linear spectral unmixing model to determine oxygen saturation in the blood of the human or animal;
- wherein the one or more processors are arranged to perform the processing by, at least:
- determining at least a first amplitude of the first photoacoustic signal and a third amplitude of the third photoacoustic signal, and
- applying at least the first and third amplitudes to the linear spectral unmixing model;
- wherein the linear spectral unmixing model is represented by:
- sO
- 2
- =
- ε
- λ
- 3
- de
- -
- r
- ′
-
- ε
- λ
- 1
- de
- (
- ε
- λ
- 3
- de
- -
- ε
- λ
- 3
- o
-
- x
-
- y
- )
- -
- r
- ′
- (
- ε
- λ
- 1
- de
- -
- ε
- λ
- 1
- o
-
- x
-
- y
- )
- where sO2 is the oxygen saturation in the blood,
- r
- ′
- =
- P
- 3
-
- F
- 1
- P
- 1
-
- F
- 3
- .
- 1
- 1
- +
- A
-
- P
- 1
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- 2
-
- δ
-
- t
- +
- AP
- 1
-
- F
- 2
-
- μ
- a
-
- 2
- F
- 1
-
- μ
- a
-
- 1
-
- e
- -
- (
- τ
- α
- +
- b
-
- v
- )
-
- δ
-
- t
- ,
- P1, P2 and P3 are the first, second, and third amplitudes, F1, F2, and F3 are optical fluences associated with the first, second, and third laser pulses, δt is a time delay between the first and second laser pulses, as well as a time delay between the second and third laser pulses, A, Σα, and b are coefficients independent of flow of the blood, μa1 and μa2 are optical absorption coefficients associated with the first and second laser pulses, ελ1,3de and ελ1,3oxy are molar extinction coefficients of oxyhemoglobin and deoxyhemoglobin at the first and third wavelengths.
127 more elements
Dependencies are inferred from the claim text.